Ozone generator with releasable connector and grounded current collector

ABSTRACT

A generator is taught which uses alternating current or pulsating direct current to produce ozone from oxygen. The generator comprises a high voltage and ground electrode separated to form a gap for accommodating a dielectric member and gas to be reacted. The generator includes many features which may be used alone or in combination to provide an energy efficient and safe apparatus.

FIELD OF THE INVENTION

This invention is directed to an apparatus for producing ozone and, inparticular, an apparatus for producing ozone using alternating currentor pulsating direct current.

BACKGROUND OF THE INVENTION

Ozone generators are known which employ corona discharge to produceozone from oxygen by action of oxygen atoms on oxygen molecules. Thesegenerators employ a high voltage alternating sinusoidal currentoperating at frequencies of between about 60 and 5,000 Hz and voltagesfrequently above 20 kilovolts. Such generators require high voltagetransformers which are difficult to construct and insulate and whichcause the generator to be very large in size.

During breakdown, oxygen or air in the gap becomes partially ionized asseveral kilovolts of energy is applied to it, and milliampere to amperecurrents result. Bemuse of the required operating frequencies andvoltages of most known generators and the fragile nature of thedielectrics of the reaction chamber, deterioration of the generatorsoften occurs, requiring maintenance and repair. The construction ofknown generators requires that the entire unit including generator,transformer and any associated electronics be shipped offsite for repairand maintenance.

To allow a better understanding of the prior art, reference may be madeto the following drawings of prior art in which FIGS. 1 and 2, each showa prior art ozone generator.

Referring to FIG. 1, a plate generator 10 is shown having a pair ofmetallic plate electrodes 12, 14 and a layer of dielectric material 20therebetween. Electrodes 12, 14 are separated to form a gap 18.

The ozone generator of FIG. 2 employs a tubular geometry and includes afirst electrode 25 and a second, larger diameter, electrode 26.Electrode 25 has a layer of dielectric material 27 disposed on thesurface thereof and is positioned within electrode 26 to form a gap 28therebetween.

In known generators, such as those shown in FIGS. 1 and 2, a highvoltage current is applied to the electrodes to produce a coronadischarge in the gap. The discharge produces ozone by ionization ofoxygen which is present in the gap.

SUMMARY OF THE INVENTION

According to a broad aspect of the present invention there is providedan apparatus for producing ozone from oxygen comprising a generatorelement having a high voltage electrode and a ground electrode separatedfrom the high voltage electrode to form a gap and a dielectric elementdisposed therebetween and occupying a portion of the gap, the generatorelement being electrically connected to a circuit for producing analternating current or pulsed direct current and the generator elementbeing removable from the circuit.

According to a further broad aspect of the present invention there isprovided an apparatus for producing ozone from oxygen comprising agenerator element having a high voltage electrode and a ground electrodeseparated from the high voltage electrode to form a gap and a dielectricelement disposed therebetween and occupying a portion of the gap, thehigh voltage electrode being electrically connected to a circuit forproducing alternating or pulsating direct current, the high voltage andground electrodes being impedance matched to the circuit.

According to a further broad aspect of the present invention there isprovided an apparatus for producing ozone from oxygen comprising agenerator element having a high voltage electrode and aground electrodeseparated from the high voltage electrode to form a gap and a dielectricelement disposed therebetween and occupying a portion of the gap, thehigh voltage electrode being electrically connected to a circuit forproducing alternating or pulsating direct current, and a groundedcurrent collector at an output of the generator element.

According to a further broad aspect of the present invention there isprovided an apparatus for producing ozone frown oxygen comprising agenerator element having a high voltage, electrode and a groundelectrode separated from the high voltage electrode to form a gap and adielectric element disposed therebetween and occupying a portion of thegap, the high voltage electrode being electrically connected to acircuit for producing alternating or pulsating direct current, thechamber being provided such that its inductance and capacitance areselected to produce a waveform within the gap having a high frequencycomponent which is selected break the oxygen--oxygen bond.

According to a further broad aspect of the present invention there isprovided an apparatus for producing ozone from oxygen comprising agenerator element having a high voltage electrode and a ground electrodeseparated from the high voltage electrode to form a gap and a dielectricelement disposed therebetween and occupying a portion of the gap, thehigh voltage electrode being electrically connected to a circuit forproducing alternating or pulsating direct current, the circuit having asaturable transformer with at least one feedback winding.

DESCRIPTION OF THE INVENTION

A generator is provided which employs alternating current or pulsatingdirect current to produce ozone from oxygen gas or oxygen-containinggas. The generator comprises a generator element comprising a groundelectrode and a high voltage electrode spaced from the ground electrodeand having a discharge gap therebetween to accommodate the gas and adielectric member. In a preferred embodiment, the generator element isof a tubular arrangement wherein the high voltage electrode is disposedwithin the ground electrode and the dielectric layer is disposedtherebetween. The generator element is formed to contain a gas andpermit flow of the gas, where desired, through the discharge gap.

The ground electrode is formed of suitable conductive metal orsemiconductive material. Where the gas flow is passed in contact withthe electrode, the ground electrode is made from a material, such as forexample, stainless steel, which is ozone inert. In an embodiment of atubular generator arrangement, the ground electrode is formed as a tubeinto which the dielectric and high voltage electrode fit. In anotherembodiment, the ground electrode is formed as a block and providessupport for the dielectric. The block electrode is formed with a channeltherethrough or in sections having alignable grooves for accommodatingthe dielectric.

The high voltage electrode is formed of materials similar to those ofthe ground electrode and is evenly spaced from the ground electrode toprovide an even capacitive load. In a generator element having a tubulargeometry the high voltage electrode is formed to fit within the groundelectrode and a discharge gap is formed therebetween. To provide an evencapacitive load in the generator, the high voltage electrode ismaintained substantially centrally within the ground electrode by anysuitable means. In an embodiment, the high voltage electrode is a wireheld centrally by means of centralizer spirals formed of an inertpolymer. Alternatively, dielectric centering blocks, such as ceramictriangles or apertured discs, can be employed. In an alternateembodiment, a spiral electrode is provided and is maintained centrallyby means of centering blocks disposed at each end of the channel inwhich the electrode is mounted. In such an embodiment, a dielectricmember can be used as a support for the spiral electrode by winding theelectrode about the member or by inserting the member into a preparedspiral electrode. The member is solid and acts to prevent the flow ofgas along the center axis of the chamber and thereby directs the gasthrough electrical discharge between the high voltage and the groundelectrodes. In another embodiment the centering blocks are formedintegral with the dielectric support member and the spiral electrode iswound thereabout.

The dielectric member which is positioned between the ground electrodeand the high voltage electrode acts as a capacitor together with the gaswhich is supplied to the generator. In one embodiment, the dielectric ispositioned in close contact with the ground electrode. Alternatively,the dielectric material is disposed about the high voltage electrode.The dielectric member is formed of a suitable dielectric material suchas a ceramic, glass or polymeric material and is preferably separate oreasily separable from the electrodes to allow for independentreplacement of the dielectric member apart from the electrodes and tofacilitate recycling of generator components. In a preferred embodiment,the dielectric member is formed of mullite ceramic.

The generator is formed to contain gas in any suitable way. Inembodiments with a tubular geometry, the gas passes between the tubularelectrodes and is contained therebetween by a pair of end caps. The endcaps provide ports for electrical contact and input and output of gas.In an embodiment, the end caps are formed as end blocks for supportingthe generator element and containing means for electrical connection andflow paths for the gas. The end blocks can be formed to prevent directaccess to the inner components. The end blocks are formed of an ozoneinert dielectric.

Contact must be provided between the electrodes and the generatorcircuit for producing the current for ozone generation. Preferably, suchcontact is releasable such that when desired, the generator element ofthe present invention can be removed from the generator for maintenanceand repair. In an embodiment, a high voltage plug connection isemployed. A plug is mounted on the generator element and incommunication with the high voltage electrode which is disposed to makecontact with a socket provided in communication with the externalcircuit. In a preferred embodiment, the high voltage electrode isconnected to the circuitry by means of a high voltage pin. The pin has afirst end which extends from the generator to form a plug and a secondend for contacting the high voltage electrode. Such contact can be apressure contact made in the aperture of a centering block into whichthe second end of the pin and an end of the high voltage electrode areeach inserted. Such a contact arrangement avoids the need for soldering.

The electrode geometry in the generator cad be selected to createimpedance in the generator circuit which matches the impedance of thecircuitry. In a plate generator arrangement, the distance between theelectrodes, the surface area of the electrodes and the density of theelectrodes, such as for example, the use of mesh electrodes or solidelectrodes, can be selected to allow for impedance matching. Impedancematching in a tubular generator can be accomplished by selecting thepitch and length of a spiral high voltage electrode or by winding aselected number of turns of a conductive wire in contact with the highvoltage or ground electrodes. Such impedance matching enhances theenergy efficiency of the generator.

To dissipate the heat produced in the generator, it is desirable toprovide a heat sink arrangement in association with the generatorelement. The heat sink can preferably also be an electrical ground forthe generator and, as such, is provided in intimate contact with theground electrode but is detachable therefrom, when desired.

To prevent a shock hazard by use of the inventive generator, shouldwater enter the generator and make contact with the high voltageelectrode, a grounded current collector can be provided at the gasoutlet to ground the current. In an embodiment, the current collector isformed as a electrically conductive conduit for carrying output gas andis grounded by contact with the ground electrode of the generator. Inanother embodiment, the current collector is a conduit formed integralwith the ground electrode and in engagement with the end blocks.

All components of the generator which are in contact with the gas mustbe built having regard to the corrosion problems of the gas to beintroduced and the ozone formed in the generator, as is known in theart.

The generator is of use with pulsating direct current or alternatingcurrent. In a preferred embodiment, oxygen--oxygen bonds are selectivelybroken by use of a high frequency, high voltage alternating current orpulsed direct current discharge which is selected to have a waveformhaving a fast rise leading edge suitable for breaking the oxygen--oxygenbond. The fast rise portion of the waveform creates a range of highfrequency components defined by the rate of change at each point on theslope in conjunction with the repetition rate and the amplitude of thewaveform. The time that the leading edge of a waveform is maintained atany given frequency combined with the voltage at that point give apotential energy transfer rate.

To break the oxygen--oxygen bonds the leading edge of the waveform isselected to have a high frequency component which breaks the oxygenmolecules apart, termed the "active frequency" or "active high frequencycomponent". This active frequency must be applied at a suitable voltageand be maintained for a sufficient time to transfer enough energy to themolecule to break the bond.

It is believed that the active high frequency component is close to aprimary or harmonic of the natural oscillating frequency of theoxygen--oxygen bond and therefore creates constructive interference withthe oscillation of any oxygen--oxygen bonds which are in phase with theapplied active frequency. It is believed that suitable activefrequencies are at least in the megahertz range. This active frequencyis applied at a suitable voltage and is maintained for a sufficient timeto transfer enough energy to the molecule to break the bond. It isbelieved that the suitable voltage is at least 3 times the combinedstrength of the bonds to be broken. It is further believed that anavalanche effect is created wherein further oxygen--oxygen bonds arebroken by those broken through the application of the active frequency.In such an effect, the release of bond energy causes the separatedoxygen atoms to be high in energy and to collide with other oxygenmolecules that are weakened from the application of the current. Due tothe collision, the oxygen--oxygen bonds of the weakened molecules arebroken. Since it is believed that the applied active frequency can be aharmonic of the natural oscillating frequency, it is also believed thatthere are many active frequencies that are suitable for interferencewith the oxygen--oxygen bond, as there are many harmonics of that bond.

In an ozone generator employing a current having an active highfrequency component, it is believed that substantially onlyoxygen--oxygen bonds are broken, even where other molecular species arepresent. However, due to ionization in the chamber and the impact ofhigh energy oxygen atoms, some side reactions may occur such as theproduction of nitrous oxides.

In an embodiment, a periodic wave form is generated having a leadingedge selected to represent an active frequency for breakingoxygen--oxygen bonds and sufficient voltage to break the bond once it isapplied. In a continuous system, wherein oxygen molecules are beingconverted to ozone and passed on, the flow rate of the molecules throughthe chamber must be considered and the voltage should be increasedaccordingly, to expose each portion of the gas containing the oxygenmolecules to sufficient voltage to initiate bond breakage before the gaspasses out of the generator.

In order to carry out the process of the present invention, thegenerator circuitry is set to apply an alternating or pulsed directcurrent having a fast rise and sufficient voltage. To obtain an activehigh frequency component and optimize the waveform for ozone production,the repetition rate of the waveform or amplitude of the current, orinductance or capacitance of the circuit transformer or generator can beadjusted while analyzing ozone production by use of a chemical analyzer,such as a mass spectrometer or ozone monitor. In a preferred embodiment,the inductance and capacitance are maintained constant, while therepetition rate and amplitude are adjusted to obtain an active highfrequency component. Once the generator is set, the ozone production cancontinue without modification at substantially similar operatingpressure and temperature. Any changes in the voltage or the repetitionrate of the applied discharge or changes in the inductance orcapacitance of the circuit generator or transformer, including changesin pressure or generator load, require reoptimization of the waveform tore-establish the active high frequency component. Such readjustment canbe made manually or by use of a circuit feedback arrangement. Inaddition, in generators produced with similar geometry, fie circuit canbe optimized once and incorporated into each further generator withoutresetting.

In one embodiment a capacitive-inductive resonating circuit is used toproduce a carrier waveform having the required active frequency for theozone production. The circuit is powered by any suitable power supply orsource. The resultant waveform can be an alternating current or a pulseddirect current having a fast rise leading edge. In a preferredembodiment, the current is an pulsating direct current having an activefrequency component and is preferably generated and maintained, by anelectronic circuit employing a saturable transformer having a feedbackwinding. The high frequency component is produced by "switching on" atransistor until the core of the transformer is magnetically saturated,as determined by the feedback winding or windings and the connectedgenerator. The "switch on" initiates oscillation at the circuitresonance frequency and once initiated the energy from the core of thetransformer maintains the reaction. In an alternate preferredembodiment, the current is a high voltage direct current having theactive frequency component added thereto.

In the preferred embodiment, the generator acts as the capacitance in aparallel resonant circuit with the secondary winding of the transformerforming the inductor. The capacitive and inductive characteristics ofthe generator cell and inductor are chosen such that the circuit isessentially resistive at the resonant, active frequency. Energy transferto the gas produces some heat and causes ozone production by interferingwith and breaking the oxygen--oxygen bond.

Since the presence of gas alters the capacitance of the resonantcircuit, the electronic circuit of the present invention is capable ofcompensating for changes in the reactor loading such as the gas flowrate, gas density, gas composition or gas temperature by sensing thechanges in the dielectric constant of the gas. Any changes in thedielectric constant of the gas causes the current of the discharge inthe generator to change, and hence the feedback winding changes theoperating repetition rate to maintain the required active frequency forozone production.

A flowing stream of gas can be fed to the generator such that acontinuous process for ozone production is set up. To increase theoutput of ozone by the generator, the length of the generator elementcan be extended or a plurality of generator elements can be provided inseries or parallel. In such arrangements, an electrical control can beprovided to detect malfunction and cause the generator to be shut down.

BRIEF DESCRIPTION OF THE DRAWINGS

A further, detailed, description of the invention, briefly describedabove, will follow by reference to the following drawings of specificembodiments of the invention, which depict only typical embodiments ofthe invention and are therefore not to be considered limiting of itsscope. In the drawings:

FIG. 1 shows a prior art ozone generator;

FIG. 2 shows another prior art ozone generator;

FIG. 3 shows a sectional view along the axis of an embodiment of agenerator element according to the present invention;

FIG. 4 shows an exploded, perspective view of another embodiment of agenerator according to the present invention;

FIG. 5 shows a sectional view though an end block of an embodiment of agenerator according to the present invention;

FIG. 6 shows a perspective view of a modular generator according to thepresent invention with a panel of the housing removed to show the innercomponents;

FIG. 7 shows a schematic diagram of a generator system according to thepresent invention;

FIG. 8 shows an oscilloscope representation of a waveform useful in thepresent invention;

FIG. 9 shows a circuit diagram of an electronic circuit useful in thepresent invention; and,

FIGS. 10A and 10B show oscilloscope representations of a waveformsuseful in the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 3, a perspective view of a generator element accordingto the present invention is shown comprising an outer ground electrode210, an inner high voltage electrode 212 and a dielectric member 214therebetween. Ground electrode 210 is formed as a sleeve which is intelescopic arrangement with dielectric member 214 but as removabletherefrom. High voltage electrode 212 is a straight length of metal suchas stainless steel and is held concentrically within the dielectricmember 214 by means of spiral centralizers 216 formed of plastic. Endcaps 218 are provided at the ends of the element to seal against thepassage of gas out of the bore of the dielectric member 214. Ports 220,221 are formed in end caps 218 for mounting gas supply and output lines222, 223, respectively. Electrical connectors 224 are mounted on endcaps 218 for connection to electrical lines 225.

Gas containing oxygen flows into the generator through port 220 andpasses through the bore of dielectric member 214. Alternating current orpulsating direct current is applied between electrodes 210 and 212, bycontact with an external power source through connectors 224 and lines225, and through the gas causing ionization and modification of themolecular species present in the gas. Gas containing ozone moves out ofthe generator through the exit port 221. A conductive layer 228 isprovided about the inner surface of exit port 221 which is in contactwith ground electrode 210 via wire 229 and thereby provides forcollection of current if water passes through it into contact withelectrode 212.

When replacement or repair of the generator components is required, thegenerator is shut down, such as by stopping supply of gas and power andremoving the supply lines. The end caps are removed and the defectiveparts are removed, including possibly the entire generator element. Anew generator element can then be connected and the generation processre-initiated.

Referring to FIG. 4, a preferred generator for ozone production isshown. The generator comprises an apparatus 23 for producing a currentcomprising a waveform having an active frequency component, a reactionchamber 24 and a heat sink arrangement 26 associated with apparatus 23and reaction chamber 24.

Reaction chamber 24 comprises ground electrodes 33 and 34 havingcorresponding grooves formed therein for accommodating and contactingdielectric tubular member 36. Electrodes 33, 34 are secured about member36 by pop rivets 38 and 40.

Disposed within member 36 is high voltage spiral electrode 42 consistingof ozone inert metal such as stainless steel. The pitch and length ofelectrode 42 is selected to impedance match the impedance of apparatus23. In addition, the length of electrode 42 is selected to prevent nodereflection at the required discharge waveform. A screw 43 formed of asuitable dielectric material is inserted through a threaded aperture 45in end ,block 60 to be in engagement with an end 52 of electrode 42which allows external adjustment of the length and pitch of electrode42. A dielectric member 44 acts as a filler and support for spiralelectrode 42. An end portion 48 of spiral electrode 42 is inserted intocentral aperture 48 of centering triangle 50. The other end 52 of spiralelectrode 42 is inserted into central aperture 54 of centering block 56.Tubular dielectric member 36 containing spiral electrode 42 andassociated parts 44, 50, 56 is inserted between apertures 66, 68 of endblocks 58 and 60, formed of suitable dielectric material, respectively.Sealing means, such as O-rings 62, 64 are provided to seal theconnection between tubular member 36 and the end blocks against passageof gas. Other sealing means can be used such as for example, siliconesealant. A high voltage pin 70 is inserted into aperture 48 of centeringblock 50 to be in electrical communication with end 46 of spiralelectrode 42. The other end of pin 70 extends through, and is engagedwithin, an aperture 71 in end block 58 for electrical communication withapparatus 23.

A current collector 72 formed as a tubular member from corrosionresistant conductive metal is sealably secured such as by press fittingat its ends into apertures 74 and 76 of end blocks 58 and 60,respectively. Current collector 72 acts mechanically to join and form agas conduit between end blocks 58 and 60. Electrodes 33 and 34accommodate and make contact with current collector 72. Since electrodes33 and 34 are at ground potential during operation and are in intimatecontact with current collector 72, current collector 72 serves toprevent electrical current from passing out of the generator elementduring use.

Referring to FIGS. 4 and 5, a stream of gas containing at least aportion of oxygen is provided to the generator through entry nozzle 78into an upper chamber 79 of block 60. Upper chamber 79 of block 60 isformed generally as an "L" shaped chamber having an extending portion79a which impedes insertion of articles, such as wires, into thegenerator to contact high voltage electrode 42. Still referring to FIG.5, screw 43 is inserted into aperture 45 to be in contact with electrode42. Electrode 42 is maintained in a recess formed in an end of screw 43and is held therein by the resiliency in electrode 42. The length ofelectrode 42 can be altered by changing the extent to which screw 43 isinserted into end block 60.

The gas is directed into and passes through dielectric tubular member 36and about spiral electrode 42 into end block 58. Dielectric member 44acts within dielectric member 36 to direct the gas into dose associationwith spiral electrode 42. The spiral configuration, in addition toproviding impedance in the generator, acts to create turbulence in thepassing gas stream and thereby enhance mixing. Such mixing allows forincreased heat transfer from electrode 42 to electrodes 33 and 34 whichare cooled by heat sink 26. Gas returns along the bore of currentcollector 72 to enter a lower chamber 73 of block 60 where an outlet 77is provided from the generator. Gas passing through this system isreacted when passing through dielectric tubular member 38 preferably byapplication of a selected active frequency current applied throughelectrode 42. Current is provided to electrode 42 by apparatus 23.

Apparatus 23 for producing current is of any suitable kind. In apreferred embodiment, apparatus 23 is comprised of a circuit, as will bedescribed in reference to FIG. 9, including among its components a highvoltage transformer 80, a low voltage transformer 82, a bridge rectifier86, a switch 109, transistor 90 and associated electronics 88. The lowvoltage transformer 82 is provided with fluctuating power such asalternating current by means of plug 84. The current produced byapparatus 23 is communicated to the generator through a high voltagewire 96 having a plug socket 98 on an end thereof for making contactwith high voltage pin 70 in end block 58. Switch 109 interrupts thepower flowing from the transformer 82 to the electronics 88 when endblock 58 is moved away from plug 98. Thermal switch 112 on heat sink 26interrupts power flowing from transformer 82 when the temperature in thegenerator exceeds a predetermined level.

When the high frequency, high voltage current is applied to the gas inthe generator, heat is generated. A heat sink 26 is provided inassociation with reaction chamber 24 to reduce temperature fluctuationsin the generator. Heat sink 26 comprises a thermally conductive tube 121which is inserted into a heat sink block 122. A suitable coolant iscirculated through tube 121. Holes in the heat sink block 122 include athreaded hole 123 to mount the transistor 90 and a threaded hole 125 tomount the bridge rectifier 86. Heat sink block 122 is firmly mounted toground electrodes 33 and 34 through conductive screws 126 which also actto ground electrodes 33 and 34. Screws 126 are easily removable to allowremoval of generator element.

Referring to FIG. 6, in the preferred embodiment, the generator isprovided in the form of a module to facilitate installation. The modulecomprises a housing 600 (shown with the top removed) formed of durablematerial such as thermoplastic. Housing 600 provides encasement for anapparatus 623 for producing current, a generator element 624 and a heatsink arrangement 626. Extending from housing 600, for connection toexternal supply lines, are plug 684 and ends 621a and 621b of thermallyconductive tube 621. Additionally, end block 660 of generator element624 extends from housing 600 to allow connection of gas lines to entrynozzle 678 and outlet 677. Generator element 624 is removably installedwithin housing 600 by insertion through aperture 697 and into abutmentwith upstanding stop 699 (generator element 624 is shown partiallyinserted in FIG. 6). Stop 699, formed of a suitable dielectric, supportshigh voltage plug socket 698 which is aligned for contact with a highvoltage pin extending through an aperture of end block 658. When inplace screws 6126 are inserted through a side wall of housing 600 toengage heat sink 626 and the ground electrodes of generator element 624.A pressure sensitive switch 6109, disposed adjacent stop 699, interruptsthe power to apparatus 623, when generator element 624 is not fullyinserted into housing 600 such that the high voltage pin is not insertedinto socket 698. Such a generator element installation arrangementallows for removal and replacement of chambers, when desired, withoutaffecting the circuitry or heat sink components.

As shown schematically in FIG. 7, the output of ozone by the presentozone generator can be increased by providing a generator systemcomprising a plurality of generator elements 724a, 724b and 724c inseries. Problems in scale-up, such as reconfiguration of enlargedgenerators, are thus avoided by installing optimized generators ingreater numbers. To control the passage of untreated gas through thesystem, in case of system failure, valves 799a, 799b and 799c areprovided at the outlet of each generator element so that gas can flowfrom element 724c through element 724b and then through element 724a.These valves are held open in normal operation by power supplied vialine 797, which is in series with the apparatus 723 for producingcurrent. Where the system fails, such as by dielectric breakdown, acurrent-sensitive protective device 795, such as a fuse or circuitbreaker, in the power supply 793 senses the increase in current andstops power to the system. Valves 799a, 799b, and 799c then stop theflow of gas through the chambers 724a, 724b and 724c until the flow ofcurrent is resumed, thereby preventing output of any unreacted gasthrough the system.

Referring to FIG. 8, a waveform is shown which is useful in theselective breaking of oxygen--oxygen bonds in oxygen molecules toproduce ozone. The active portion of the waveform is shown between A andB. From the oscilloscope, calculations of the slope of the substantiallystraight rise portion of the leading edge between A and B indicate thatthe rate of voltage increase over this portion is in the order of6.6×10⁶ volts/second. Such an active portion is believed to correspondto a frequency in the order of 10 to 100 megaHz. The waveform is appliedat a repetition rate of about 6.67 kHz to air at a temperature of 26° C.and atmospheric pressure to produce ozone. Ozone generation is enhancedby applying the waveform to air at lower temperatures. The generator ofuse with the waveform having parameters as shown is generally as shownin FIG. 4 and is 4 to 8 inches in length having a corresponding lengthhigh voltage electrode having 22 turns and formed from 0.036 inchstainless steel wire.

Referring to FIG. 9, a preferred embodiment of a circuit is shown foruse in generating current comprising a waveform as shown in FIG. 8. Thecircuit comprises a Darlington pair transistor T1 and a ferrite coretransformer TR1. The transformer TR1 has four windings, the primarywinding 300, a secondary (output) winding 310, and two feedback windings320 and 330. The primary winding 300 connects the collector of thetransistor T1 to the positive power supply voltage. The secondarywinding 310 is the output of the generator circuit and is applied to oneof the electrodes of the reactor cell shown in FIG. 3. The feedbackwinding 320 is connected via diode D4 and R3 to the base of thetransistor T1. The other terminal of the feedback winding 320 isconnected to the biasing circuit of the transistor T1, which comprisesvariable resistor VR1, resistor R1 and resistor R2, as well as siliconswitching diodes D1, D2 and D3. The feedback winding 330 connects theemitter of the transistor T1 to the negative terminal of the powersupply. The circuit operates as follows.

Transistor T1 is present to permit the generation of a fast risewaveform. In a circuit which is intended to produce pulsed DC waveforms,one transistor T1 is used. If it is desired to produce AC waveforms, asecond transistor (not shown) is used. As the transistor T1 is handing ahigh peak current, a heat sink to dissipate the heat generated by suchcurrent should be used.

Transformer TR1 is a saturable transformer having a ferrite corematerial with very low losses. In a preferred embodiment, TR1 has aferrite core comprising a 7 turn primary winding 300, a 3 turn feedbackwinding 320, a 1 turn feedback winding 330 and a secondary winding 310having 3300 turns of 22 gage wire.

The diodes D1, D2,. D3, and D4 are silicon switching diodes that areselected to have voltage and temperature characteristics whichcorrespond the Darlington transistor. Diodes D1, D2, and D3 give aregulated "switch on" voltage for transistor T1. Diode D4 acts toprevent the negative feedback voltage turning the base-emitter junctionof transistor T1 back "on" by reverse voltage avalanche breakdown. Anysimilar silicon switching diode to IN914 can be used for diodes D1, D2,D3, and D4.

Variable resistor VR1 and fixed resistor R1 regulate the current tomaintain the voltage across the diodes and bias the base of thetransistor T1. Variable resistor VR1 is used to set the operatingcurrent, compensating for different gain of transistors, Resistor R1acts to limit the current when variable resistor VR1 is set to 0.Alternatively, a faced value resistor of suitable resistance for thetransistor used, can replace both R1 and VR1.

Feedback winding 330 is connected to the emitter of the transistor. Itprovides compensation for change of gain versus temperature, andprovides some compensation for transistors of different gain. Winding330 is most useful in high power reactors, However, since it also actsto damp harmonics in the system, which would interfere with the desiredactive frequency, it is preferably included in all circuits.

Capacitor C1 reduces variations in the supply voltage reaching the baseof transistor T1 during normal operation. This is important in highcurrent generators. Due to the high switching current, smoothingcapacitors C1 and C2 must each handle high peak ripple currents and mustbe rated accordingly.

Power is applied to the circuit by an AC source, as shown. The currentwithin the circuit is preferably 12 volt DC. Therefore where 120 voltpower is used a step down transformer is required prior to the bridgerectifier BR1. The bridge rectifier is useful even where the powersupply is a battery, since the rectification allows connection of thebattery without concern as to matching terminals.

After power is applied to the circuit, the base of transistor T1 isdriven positive and the collector current increases. For the purposes ofthis description, it is assumed that the circuit has been operating forsome time and that we are starting the description from the point wherethe base of transistor T1 is being driven positive and the collectorcurrent is increasing.

With translator T1 fully switched on, the current through the primarywinding of TR1 transformer increases at a rate set by the transformerinductance and the generator capacitance. As the current increases, thetransformer core magnetizes, and a voltage is induced into the basefeedback winding 320. The negative going end of feedback winding 320 isconnected to the voltage reference diodes D1, D2, D3 and the positivegoing end connected through diode D4 to resistor R2 and the base oftransistor T1. Thus, an induced voltage in feedback winding 320 acts tomaintain transistor T1 "on". The actual drive current is set by thevalue of the resistors VR1 end R1.

Resistor R3 together with the base input capacitance of transistor T1reduces current oscillation at very high frequency during switching,Preferably, resistor R3 is connected directly at the base of transistorT1.

As the transformer core approaches saturation, the rate of currentincrease drops. As it drops, the induced voltage in the base feedbackwinding reduces thus reducing the drive to the transistor, which thenstaffs to turn off. This reduces the rate of increase of the collectorcurrent through primary winding 300 and this in turn further and furtherreduces the feedback voltage. This very rapidly turns the transistorfully off. As the core magnetic field is no longer being maintained bythe transistor, the magnetic field collapses reversing the voltage inthe base feedback winding 320 and placing a negative voltage on theanode of diode D4 turning it off thus keeping transistor T1 turned off.This also effectively unloads the feedback winding 320 and prevents anydamping of the now oscillating secondary winding 310.

As the current drops towards zero across the base of feedback winding320, the generated negative voltage across the base feedback winding 320decreases until it no longer cancels the bias voltage at the cathode ofdiode D1. When this happens, the transistor starts to turn on. As itdoes, the current starts increasing and this in turn reverses thevoltage in the base feedback winding 320. This applies additionalpositive voltage to the base of transistor T1 turning it fully on andinto full saturation. Now the transistor is turned fully on and thecollector current increases, which is where the cycle repeats.

The invention will be further illustrated by the following examples.While the examples illustrate the invention, they are not intended tolimit its scope.

EXAMPLE 1

Air at atmospheric pressure and 26° C. was dehumidified such that it hada dew point between 35° and 40° F. The air was introduced to a ozonegenerator, generally as described in reference to FIG. 4, at a flow rateof 3 l/min. Air exiting the generator was passed to an ozone monitor foranalysis.

Electrical discharges were applied to the air as follows:

1. A sinusoidal waveform having a frequency of 60 Hz and varied between5,000 and 8,000 volts;

2. A sinusoidal waveform having a frequency of 6.5 kHz and rangingbetween 5,000 and 8,000 volts;

3. A square waveform having a frequency of 6.5 kHz and ranging between5,000 and 8,000 volts; or,

4. A waveform according to FIG. 8 at a repetition rate of 6.67 kHz andan amplitude of 4,500 volts.

Typical ozone production results by use of waveforms 1 to 4 fortreatment of air are summarized in Table 1.

                  TABLE 1                                                         ______________________________________                                                     Ozone concentration                                              Waveform     (% by weight)                                                    ______________________________________                                        1            0.001                                                            2            0.066                                                            3            0.066                                                            4            0.332                                                            ______________________________________                                    

Conversion rates were increased by use of the fast rise waveformaccording to the present inventive process.

EXAMPLE 2

Air at atmospheric pressure and 22° C. and having a relative humidity of80% was introduced at a flow rate of 3.8 l/min to ozone generators,generally as described in reference to FIG. 4 without the use of a heatsink and having the parameters as set out in Table 2.

                  TABLE 2                                                         ______________________________________                                                  Ozone generator A                                                                         Ozone generator B                                       ______________________________________                                        Length      12       inch     4      inch                                     Capacitance 147      pF       34     pF                                       (at frequency = 0)                                                            Resonance   58.2     Mhz      66.0   Mhz                                      Inductance  0.0508   uH       0.170  uH                                       ______________________________________                                    

The measurements for the generators were carried out in 18° C.,atmospheric pressure and 70% RH using a MIC37 multimeter and a MFJHF/VHF SWR analyzer, to measure capacitance and resonance, respectively.Inductance was calculated.

The waveform was monitored using a Phillips PM3365A 100 MHz Oscilloscopeset at 5 VDC and 0.1 ms connected to a Techtronix P6015 1000× probe. Airexiting the generator was passed to an ozone monitor for analysis.

The waveforms which were found to produce optimum amounts of ozone forgenerator A and generator B are shown in FIGS. 10A and 10B,respectively. The waveform parameters and ozone production results areshown in Table 3.

                  TABLE 3                                                         ______________________________________                                                    Ozone generator                                                                          Ozone generator                                                    A          B                                                      ______________________________________                                        Repetition rate (Hz)                                                                        1603         1637                                               Voltage (kV)  20           22                                                 Leading edge rate of                                                                        234 × 10.sup.6                                                                       233.5 × 10.sup.6                             voltage increase (V/s)*                                                       Ozone concentration                                                                         0.190        0.145                                              (% by weight)                                                                 ______________________________________                                         *determined from oscilloscope                                            

The active frequency for ozone production is uniform for gas having thesame composition, flow rate, temperature and pressure regardless of thereactor parameters. The active frequency can be determined for eachreactor by adjusting the amplitude and repetition rate.

EXAMPLE 3

Air at atmospheric pressure and 22° C. and having a relative humidity of80% was introduced at a flow rate of 3.8 l/min to ozone generator A asdescribed in Example 2. The waveform was monitored using a PhillipsPM3365A 100 MHz Oscilloscope set at 5 VDC and 0.1 ms connected to aTechtronix P6015 1000× probe. Air exiting the generator was passed to anozone monitor for analysis.

The waveform was changed from waveform 1, having a slower rate ofvoltage increase than the waveform of FIG. 10A, to waveform 2, accordingto FIG. 10A, by adjusting the power to the generator. Results are shownin Table 4.

                  TABLE 4                                                         ______________________________________                                                     Ozone Concentration                                              Waveform     (% by weight)                                                    ______________________________________                                        1            0.021                                                            2            0.190                                                            ______________________________________                                    

It will be apparent that many other changes may be made to theillustrative embodiments, while falling within the scope of theinvention and it is intended that all such changes be covered by theclaims appended hereto.

We claim:
 1. An apparatus for producing ozone from oxygen comprising agenerator element having a high voltage electrode, a ground electrodeseparated from the high voltage electrode to form a gap therebetween,and a dielectric element occupying a portion of the gap, the generatorelement being electrically connected to a circuit for producing analternating current or pulsed direct current by means of a releasableconnector, said high voltage electrode extending into a spacer, and saidreleasable connector connecting the high voltage electrode through saidspacer to said circuit.
 2. The apparatus of claim 1 wherein thereleasable connector is a high voltage plug connected to high voltageelectrode and registering with a high voltage socket in communicationwith the circuit.
 3. The apparatus of claim 1 wherein the plug is a pin,having one end extending through the end cap to make contact with thehigh voltage electrode and a socket in communication with the circuit.4. The apparatus of claim 1 wherein a housing is disposed about thegenerator element and circuit, and the generator element is removablefrom the housing.
 5. The apparatus of claim 1 wherein a heat sink isdisposed in contact with the generator element.
 6. The apparatus ofclaim 1 further comprising a switch for interrupting power to thecircuit when the generator element is removed from the circuit.
 7. Theapparatus of claim 1 wherein the dielectric member is a tubular member,accommodated within and in contact with the ground electrode and thehigh voltage electrode is disposed within the dielectric member.
 8. Theapparatus of claim 7 wherein the generator element further comprises anend cap at each end thereof.
 9. The apparatus of claim 8 wherein eachend cap is formed as a block having a chamber for passage of gastherethrough, each said block having an aperture for insertion of thedielectric member therein such that a continuous passage is formedbetween the end blocks.
 10. The apparatus of claim 7 further comprisinga grounded current collector at an outlet from the generator element.11. The apparatus of claim 10 wherein the current collector is aconductive gas conduit and is accommodated within the ground electrode.12. The apparatus of claim 9 further comprising a grounded currentcollector at an outlet from the generator element.
 13. The apparatus ofclaim 12 wherein the current collector is formed as a conductive gasconduit, having its ends inserted into the end caps and is accommodatedwithin the ground electrode.
 14. The apparatus of claim 1 wherein thehigh voltage electrode is a spiral electrode having a selected pitch andlength, further comprising a dielectric member disposed within thespiral electrode, and further comprising a means for adjusting the pitchand length of the spiral electrode.
 15. The apparatus of claim 14wherein the means for adjusting the pitch and length of the spiralelectrode is a dielectric screw in contact with the spiral electrode.16. An apparatus for producing ozone from oxygen comprising a generatorelement having a high voltage electrode, a ground electrode separatedfrom the high voltage electrode to form a gap therebetween, end adielectric element occupying a portion of the gap, the high voltageelectrode being electrically connected to a circuit for producingalternating or pulsating direct current, and a grounded currentcollector at an outlet to the generator element.
 17. The apparatus asdefined in claim 16 wherein the current collector is conductive tubularmember for passage of gas therethrough and in electrical contact withthe ground electrode.
 18. The apparatus as defined in claim 17 whereinthe tubular member is accommodated within the ground electrode.
 19. Theapparatus as defined in claim 16 further comprising a first end cap at afirst end of the generator element and a second end cap at an oppositeend of the generator element and the tubular member engaged between thefirst end cap and the second end cap.
 20. An apparatus for producingozone from oxygen comprising a generator element comprising a reactionchamber having a high voltage electrode, a ground electrode separatedfrom the high voltage electrode to form a gap therebetween, and adielectric element occupying a portion of the gap, the high voltageelectrode being electrically connected to a circuit for producingalternating current or pulsating direct current, the reaction chamberbeing provided such that its inductance and capacitance are selected toproduce a waveform within the gap having an active high frequencycomponent which is selected to break apart the oxygen, furthercomprising means capable of optimizing the waveform by adjusting itsleading edge slope while analyzing the apparatus output for ozone, andsetting the leading edge at a slope which yields a highest percentoutput of ozone.
 21. The apparatus of claim 20 wherein the highfrequency component is a primary or harmonic of the natural oscillatingfrequency of the oxygen molecule's oxygen--oxygen bond.
 22. Theapparatus of claim 20 wherein the waveform is produced on high voltagedirect current.
 23. The apparatus as defined in claim 20 wherein thehigh voltage electrode and the ground electrode have a geometry selectedto be impedance matched to the circuit.
 24. The apparatus as defined inclaim 20 wherein the high voltage electrode has a length selected toprevent node reflection.
 25. An apparatus for producing ozone fromoxygen comprising a generator element having a high voltage electrode, aground electrode separated from the high voltage electrode to form a gaptherebetween, and a dielectric element occupying a portion of the gap,the high voltage electrode being electrically connected to a circuit forproducing alternating or pulsating direct current, the circuit having asaturable transformer with at least one feedback winding.
 26. Theapparatus of claim 25 wherein the circuit comprises a second feedbackwinding in the emitter of the transistor.
 27. A ozone generator systemcomprising: a plurality of generator elements, each generator elementhaving a high voltage electrode, a ground electrode separated from thehigh-voltage electrode to form a gap therebetween and a dielectricelement occupying a portion of the gap; and, a circuit for producingalternating or pulsating direct current electrically connected to thehigh voltage electrode of each generator element, further comprising avalve at the outlet of each generator, each valve being an electricalvalve and in series with the circuit; and, a current-sensitiveprotection device in communication with the circuit and valves forinterrupting the current to the circuit and the valves when the currentexceeds a predetermined value.
 28. An apparatus for producing ozone fromoxygen comprising a generator element having a high voltage electrode, aground electrode separated from the high voltage electrode to form a gaptherebetween, and a dielectric element occupying a portion of the gap,the generator element being electrically connected to a circuit forproducing an alternating current or pulsed direct current by means of areleasable connector, and a grounded current collector at an outlet fromthe generator element, wherein the dielectric member is a tubularmember, accommodated within and in contact with the ground electrode,and the high voltage electrode is disposed within the dielectric member.29. The apparatus of claim 28 wherein the current collector is aconductive gas conduit and is accommodated within the ground electrode.30. An apparatus for producing ozone from oxygen comprising a generatorelement having a high voltage electrode, a ground electrode separatedfrom the high voltage electrode to form a gap therebetween, and adielectric element occupying a portion of the gap, the generator elementbeing electrically connected to a circuit for producing an alternatingcurrent or pulsed direct current by means of a releasable connector,wherein the dielectric member is a tubular member, accommodated withinand in contact with the ground electrode and the high voltage electrodeis disposed within the dielectric member, the generator element furthercomprises an end cap at each end thereof, each end cap is formed as ablock having a chamber for passage of gas therethrough, each said blockhaving an aperture for insertion of the dielectric member therein suchthat a continuous passage is formed between the end blocks, and furthercomprising a grounded current collector at an outlet from the generatorelement.
 31. The apparatus of claim 30 wherein the current collector isformed as a conductive gas conduit, having its ends inserted into theend caps and is accommodated within the ground electrode.
 32. Anapparatus for producing ozone from oxygen comprising a generator elementhaving a high voltage electrode, a ground electrode separated from thehigh voltage electrode to form a gap therebetween, and a dielectricelement occupying a portion of the gap, the high voltage electrode beingelectrically connected to a circuit for producing alternating orpulsating direct current, the high voltage and ground electrodes havinga geometry selected to be impedance matched to the circuit, wherein thehigh voltage electrode is a spiral electrode having a selected pitch andlength, further comprising a dielectric member disposed within thespiral electrode, and means for adjusting the pitch and length of thespiral electrode.
 33. The apparatus of claim 32 wherein the means foradjusting the pitch and length of the spiral electrode is a dielectricscrew in contact with the spiral electrode.
 34. An ozone generatorsystem comprising: a plurality of generator elements, each generatorelement having a high voltage electrode, a ground electrode separatedfrom the high voltage electrode to form a gap therebetween and adielectric element occupying a portion of the gap; and, a circuit forproducing alternating or pulsating direct current electrically connectedto the high voltage electrode of each generator element; and, a valve atthe outlet of each generator, each valve being an electrical valve andin series with the circuit; and, a current-sensitive protection devicein communication with the circuit and valves for interrupting thecurrent to the circuit and the valves when the current exceeds apredetermined value.